DeBardeleben, Hilary et al. (2021) International Worm Meeting "Transcriptional response to UVC irradiation in sleep deficient animals"

Raizen, David, Hare-Harris, Abby, DeBardeleben, Hilary

[International Worm Meeting, 2021]

Sleep is an important and conserved behavioral phenomenon in animals. In C. elegans, there are two distinct sleep states, one during lethargus called developmentally timed sleep and stress-induced sleep. The function of sleep is still largely unknown. Many hypothesize that it is a restorative state that allows resources to be allocated to cell processes, such as DNA damage repair. Stress-induced sleep is largely dependent on the ALA neuron and genetic mutants that lack the ALA neuron do not sleep following stress. Recently, UVC irradiation has been established as a strong and consistent inducer of sleep, also dependent on the ALA neuron. There is a strong transcriptional response following UVC irradiation. We asked if this transcriptional response supports the restorative function of sleep. We irradiated wild-type and ALA/sleep deficient mutants and did whole genome microarrays to look for differentially regulated pathways that tracked with the sleep phenotype. We also measured the transcriptional response to UVC in animals deficient in a germline. This allowed us to see the somatic cells' response to UVC irradiation, with and without the sleep behavior. Using gene module analysis we discovered differential regulation of several gene modules across groups, notably in the oxidative damage pathway. We also used Kegg pathway analysis and saw differences in regulation of longevity and axon regeneration pathways. These changes could lead to a basis for understanding the function of sleep and what pathways are important for repair and restoration during stress-induced sleep.

Smith SA et al. (2011) ILAR J "Culture and maintenance of selected invertebrates in the laboratory and classroom."

Mainous ME, Scimeca JM, Smith SA

[ILAR J, 2011]

Invertebrate species have been used for many years in the laboratory and teaching environment. We discuss some of the most commonly maintained invertebrates--the nematode (Caenorhabditis elegans), the California sea hare (Aplysia californica), the fruit fly (Drosophila melanogaster), terrestrial hermit crabs, the horseshoe crab (Limulus polyphemus), and cephalopods--and briefly describe general techniques for culturing them in captivity. The aim of this article is to give potential users an idea of the materials, methods, and effort required to maintain each type of organism in a laboratory or classroom setting.

Karn J et al. (1982) "unc-54 myosin heavy-chain gene of C. elegans: Genetics, sequence, structure."

McLachlan AD, Karn J, Barnett L

[1982]

The small soil nematode Caenorhabditis elegans is an attractive organism for the molecular study of muscle function and development because of its anatomical simplicity and suitability for genetic and biochemical analysis (Brenner 1974; Sulston and Horvitz 1977). The body-wall musculature of C. elegans is composed of 95 cell disposed in four quadrants, which run the length of the animal beneath the cuticle. The musculature is obliquely striated, and the sarcomeres are oriented parallel to the long axis of the animal. Since these cells represent a large reaction of the animal mass, isolation of contractile proteins is comparatively simple (Epstein et al. 1974; Waterston et al. 1974, 1977a; Harris and Epstein 1977; Mackenzie and Epstein 1980). Mutants affecting the characteristic pattern of motility of C. elegans can be easily identified, and microscopic examination of these "uncoordinated," or unc strains, in the living animal by polarized light microscopy or, more carefully, by electron microscopy has led to the identification of 22 genes that produce altered muscle phenotypes (Waterston et al. 1980; Zengel and Epstein 1980). Of these, two are known to code for major structural proteins of muscle: The unc-54 gene codes for the major heavy chain of myosin (Epstein et al. 1974; MacLeod et al. 1977b), whereas the un-15 gene codes for paramyosin, the core protein of the thick filaments (Waterston et al. 1974; MacLeod et al. 1977a; Harris and Epstein 1977).

Han M (1997) Cell "Gut reaction to Wnt signaling in worms."

Han M

[Cell, 1997]

The demonstrations in two papers in this issue of Cell (Rocheleau et al., 1997; Thorpe et al., 1997) of the involvement of a Wnt pathway in very early embryogenesis in Caenorhabditis elegans provides another significant step toward the ambitious but realistic goal of understanding all the basic strategies used to control embryogenesis in this model organism. At the same time, they challenge some of the prevailing models of Wnt signaling, suggesting that interactions among Wnt pathway components may vary in different developmental processes. With these papers, as well as the earlier reports on Wnt pathway genes lin-44, lin-17, and pop-1 (Herman et al., 1995; Lin et al., 1995; Harris et al., 1996; Sawa et al., 1996) and new studies on Wnt pahtway genes reported in recent meetings, worm breeders have become a significant force in the army of Wnt researchers. They have also illustrated how different systems can provide important new complementary insights.

Robertson HM (2015) Chem Senses "The Insect Chemoreceptor Superfamily Is Ancient in Animals."

Robertson HM

[Chem Senses, 2015]

The insect chemoreceptor superfamily consists of 2 gene families, the highly diverse gustatory receptors (GRs) found in all arthropods with sequenced genomes and the odorant receptors that evolved from a GR lineage and have been found only in insects to date. Here, I describe relatives of the insect chemoreceptor superfamily, specifically the basal GR family, in diverse other animals, showing that the superfamily dates back at least to early animal evolution. GR-Like (GRL) genes are present in the genomes of the placozoan Trichoplax adhaerens, an anemone Nematostella vectensis, a coral Acropora digitifera, a polychaete Capitella teleta, a leech Helobdella robusta, the nematode Caenorhabditis elegans (and many other nematodes), 3 molluscs (a limpet Lottia gigantea, an oyster Crassostrea gigas, and the sea hare Aplysia californica), the sea urchin Strongylocentrotus purpuratus, and the sea acorn Saccoglossus kowalevskii. While some of these animals contain multiple divergent GRL lineages, GRLs have been lost entirely from other animal lineages such as vertebrates. GRLs are absent from the ctenophore Mnemiopsis leidyi, the demosponge Amphimedon queenslandica, and 2 available chaonoflagellate genomes, so it remains unclear whether this superfamily originated before or during animal evolution.

Tanii I et al. (1985) J Biochem "ATPase characteristics of myosin from nematode Caenorhabditis elegans purified by an improved method. Formation of myosin-phosphate-ADP complex and ATP-induced fluorescence enhancement."

Inoue A, Tanii I, Osafune M, Arata T

[J Biochem, 1985]

Myosin was purified rapidly from the nematode Caenorhabditis elegans by an improved method. Crude actomyosin was extracted from the worms at low ionic strength. Paramyosin was removed by repeating the precipitation of myosin filaments in the presence of Mg2+ and the dissolution of them in 0.6 M NaCl. Actin was removed by ultracentrifugation in the presence of Mg-ATP and finally by column chromatography on DEAE-cellulose. This method gave a good yield of myosin (20-30 mg from 50 g wet weight of worms), and its EDTA(K+)-ATPase activity was about 3-fold higher than that of myosin prepared by the method of Harris and Epstein (1979). ATP hydrolysis by nematode myosin showed an initial Pi-burst due to formation of the myosin-phosphate-ADP complex. Tryptophan fluorescence of myosin was enhanced about 8% by ATP. The relationship between the structure and function of myosin is discussed based on the above results and the amino acid sequences of myosins from rabbit skeletal muscle and Caenorhabditis elegans.

Philip M Meneely et al. (2004) East Coast Worm Meeting "him genes and X chromosome meiosis"

Kathryn Crozier, Philip M Meneely, Joshua Havassy

[East Coast Worm Meeting, 2004]

The him genes are proving to be a rich source of information about meiosis in C. elegans. Two genes, him-5 and him-8, affect the X chromosome much more strongly than they do the autosomes. However, they appear to do this by quite distinct methods. Recessive alleles of him-8 resemble mutations of the X chromosome pairing center and have no effect on the autosomes. A collaboration between us and Abby Dernberg's lab has shown that him-8 encodes a C2H2 zinc finger protein that binds specifically at the X chromosome pairing center. Binding of HIM-8 at this region is essential for X-chromosome pairing by an unknown mechanism. In contrast, him-5 affects the X chromosome much more strongly than the autosomes, but autosomal effects are seen. We find that him-5 mutants are desynaptic, and the initial events of pairing and synapsis occur normally before the homologues come apart prematurely at diakinesis. him-5 encodes a small and extremely basic protein, with no significant similarity to any other protein but with overall similarity to many different chromosomal proteins. From antibody staining, HIM-5 is found exclusively in germline nuclei and may be loaded onto chromosomes extremely early in germline development in pre-meiotic nuclei. We have seen no evidence for specific localization of HIM-5 to a particular chromosome or a particular structure. This suggests that the effect of him-5 on meiosis is mediated through other properties of the X chromosome, not yet defined.

James B Endres et al. (2002) West Coast Worm Meeting "A Wnt gradient may guide HSN migration."

James B Endres, Shaun Cordes, Gian Garriga, Nancy Hawkins

[West Coast Worm Meeting, 2002]

The migration of neuronal cell bodies is a critical feature of neural development in all animal phyla. To investigate the molecular mechanisms of this process, we study the migrations of the hermaphrodite specific neurons (HSNs) of Caenorhabditis elegans. The HSNs are born in the tail of the comma-stage embryo and migrate anteriorly to the midbody. Later, during postembryonic development, the HSNs extend axons and synapse onto vulval muscles to control egg laying. Migrations of both the HSNs (Desai et al. 1988) and the Q neuroblasts (Harris et al. 1996) require the function of the egl-20 gene, which encodes a Wnt homolog. Wnts are secreted glycoproteins with diverse functions in many developmental processes. Desai et al. (1988) demonstrated that loss of egl-20 leads to posterior displacement (undermigration) of the HSNs, and we have observed that EGL-20 overexpression leads to anterior displacement (overmigration). Endogenous EGL-20 is expressed in the embryonic tail during the stage when the HSNs are migrating, raising the possibility that an EGL-20 gradient guides HSN migration. In contrast, EGL-20 plays a permissive role in Q cell migration by controlling mab-5 expression (Maloof et al. 1999). Supporting the possibility that an EGL-20 gradient is essential for HSN migration, global overexpression of EGL-20 from a heat-shock promoter leads to both overmigration and undermigration of the HSNs.

Ellis, Renae et al. MicroPubl Biol

Harris, Gareth, Ellis, Renae

[MicroPubl Biol, 2020]

An environment is often represented by numerous sensory cues. In order to better survive, an animal often needs to detect and process sensory cues simultaneously to make an appropriate behavioral decision. The Caenorhabditis elegans (C. elegans) genome encodes homologues of a significant number of molecules expressed in mammalian brains, which allows characterizing of the molecular and circuit basis for multi-sensory behavior during decision-making (Bargmann, 1998). In addition, studies have demonstrated various genes and neurons in behavioral differences previously observed in sensory behavior and decision-making when comparing different organisms, such as, nematodes. These variations in behavior involve differences in neuronal signals and neurons. For example, catecholamine signaling, neuropeptide Y-like receptors and pheromone chemoreceptors (Debono and Bargmann, 1998, Srinivasan et al., 2008; Bendesky et al., 2010, Mcgraph et al., 2011). In this study, we investigate the behavioral differences across various species of nematodes, by examining multiple types of Caenorhabditis species and how they may differ in a multi-sensory behavioral assay (Harris et al., 2019). The multisensory behavioral assay involves examining how different species of nematodes that are exposed to conflicting cues, behave when compared to the standard wild type, C. elegans Bristol N2 worms. We use a multi-sensory behavior paradigm to address these questions to determine any difference in 2-nonanone-dependent food leaving, that assesses food leaving during exposure to the repellent 2-nonanone. Wild type N2 C. elegans were examined as the control in comparison to other Caenorhabditis species, including, Caenorhabditis remanei (C. remanei), Caenorhabditis nouraguensis (C. nouraguensis), and Caenorhabditis portoensis (C. portoensis).

Chung, Kevin et al. (2015) International Worm Meeting "The neuronal basis of bacterial food odor preference."

Chambers, Melissa, Kan, Emily, Ota, Ryan, Chung, Kevin, Haynes, Lillian, Glater, Elizabeth

[International Worm Meeting, 2015]

Caenorhabditis elegans uses chemosensation to distinguish among various species of bacteria, their major food source 1-3. Although the neurons required for the detection of specific food-odors have been well-defined, less is known about the sensory circuits underlying the discrimination among the mixtures of odors released by different kinds of bacteria. We are examining the neural machinery underlying bacterial preference among a diverse set of bacterial species. Specifically, we are testing the food preferences of C. elegans for bacteria found in their natural habitats (kindly provided by Marie-Anne Felix, Institute of Biology of Ecole Normale Superieure, Paris, France). We have found that C. elegans prefers the odors of most species tested over E. coli. We have identified that the olfactory neuron AWC is involved in many preferences. We also find that some bacterial choices involve multiple sensory neurons with opposing roles. For example, in one choice in which wild-type animals prefer Providencia sp. (JUb39) over E. coli, the AWC neuron appears to be involved in increased preference for Providencia and the AWA neuron in increased preference for E. coli. In the future we will extend our analysis to additional bacterial species to determine the diversity of the underlying neuronal mechanisms.1. Harris, G. et al. Dissecting the Signaling Mechanisms Underlying Recognition and Preference of Food Odors. J. Neurosci. 34, 9389-9403 (2014).2. Ha, H. et al. Functional Organization of a Neural Network for Aversive Olfactory Learning in Caenorhabditis elegans. Neuron 68, 1173-1186 (2010).3. Shtonda, B. B. & Avery, L. Dietary choice behavior in Caenorhabditis elegans. J. Exp. Biol. 209, 89-102 (2006).